translate {parsnip}

Resolve a Model Specification for a Computational Engine

Description

translate() will translate a model specification into a code object that is specific to a particular engine (e.g. R package). It translates generic parameters to their counterparts.

Usage

translate(x, ...)

## Default S3 method:
translate(x, engine = x$engine, ...)

Arguments

x

A model specification.

...

Not currently used.

engine

The computational engine for the model (see ?set_engine).

Details

translate() produces a template call that lacks the specific argument values (such as data, etc). These are filled in once fit() is called with the specifics of the data for the model. The call may also include tune() arguments if these are in the specification. To handle the tune() arguments, you need to use the tune package. For more information see https://www.tidymodels.org/start/tuning/

It does contain the resolved argument names that are specific to the model fitting function/engine.

This function can be useful when you need to understand how parsnip goes from a generic model specific to a model fitting function.

Note: this function is used internally and users should only use it to understand what the underlying syntax would be. It should not be used to modify the model specification.

Examples

lm_spec <- linear_reg(penalty = 0.01)

# `penalty` is tranlsated to `lambda`
translate(lm_spec, engine = "glmnet")

# `penalty` not applicable for this model.
translate(lm_spec, engine = "lm")

# `penalty` is tranlsated to `reg_param`
translate(lm_spec, engine = "spark")

# with a placeholder for an unknown argument value:
translate(linear_reg(penalty = tune(), mixture = tune()), engine = "glmnet")